Shoe construction



Jan. 21, 1947. R. E. cAl-uLL 2,414,445

SHOE CONSTRUCTION Filed Sept. 1, 1944 4 Sheets-Sheet 1 5 arsa/ Base fikfafarsal Shank INVENTOR. ROBERT E. CAHILL. BY

ATTORNEY,

Jan. 21,1947. E, CAHILL- 2,414,445

SHOE CONSTRUCTION Filed Sept. 1. 1944 I 4 Sheets-Sheet 2 INVENTOR.

2a. Rabi/VT f. CAH LL.

ATTORNEY.

Jan. 21, 1947. R. E. CAHILL SHOE CONSTRUCTION Filed Sept. 1, 1944 4 Sheets-Sheet I I 3 I 1,

- I INVENTOR. ROBERT E. CAM/LL.

ATTORNEY.

Jan. 21, 1947. R. E. CA HILL SHOE CONSTRUCTION Filed Sept. 1, 1944 4 Sheets-Sheet 4 INVENTORV ROBERT E. CAH/LL.

ATTORNEY.

Patented Jan. 21, 1947 I UNITED STATES PATENT OFFICE Robert E. Cahill, Pasadena, Calif. Application September 1, 1944, Serial No. 552,242

9 Claims.

My invention relates to the art of making shoes and has particular reference to a new and improved member for elevated support in shoes and the method of manufacturing the same.

In the art of manufacturing shoes, particularly shoes of the type having elevated support, the constructions may be said to fall into one of two categories: (1) Those shoes having the elevated portion, 1. e. heel, and tread connected by a shank affording flexibility from heel breast to the ball of the foot. This type of shoe permits free muscle play but results in severe foot strain because three arches of the foot, viz., inner longitudinal, outer longitudinal, and transverse do not receive proper support at the base of the fifth metatarsal. (2) Those shoes having substantially rigid support from the heel portion to the ball of the foot. This group comprises all shoes other than the flexible shank type, i. e. shanks that are made of metal, wood, fiber. or the so-called wedge heel. Such shoes have one foot comfort defect in common. The more or less rigid 'area from the breast of the heel to the ball of the foot prevents the foot from functioning properly by interfering with proper function of muscles, ligamentsand nerves as well as circulation of blood and lymph.

Normal feet are of many sizes and various shapes but all have basic anatomical and physe iological characteristics in common. Thus, all normally constructed feet have the same bone weight bearingpoints in common in a properly constructed shoe. I believe that these are the heel bone, the base of the fifth metatarsal, and the heads of the five metatarsals. Firm support for those at correct relative elevations insure proper distribution of weight on the foot and consequently correct balance. This is true regardless of height of individual arches and whether or not individual feet are balanced properly or are off center in a manner described by the medical profession as eversion or pronation. It is a broad object of this invention to provide a shoe construction recognizing these facts, and affording the needed support at the points enumerated without restrictive or binding elements where support is not needed and where free flow of foot muscles should be encouraged. In embodying this invention in a shoe, support for the heads of tlie flve metatarsals is furnished primarily by the ground upon which the outsole of the shoe rests. The elevated support-is furnished by a heel and a post, as subsequently described.

It is an object of this invention to provide a shoe having a new and novel type of elevated support in lieu of a conventional heel, or heel and shank.

Another object is to provide an elevated member'for a shoe giving support where anatomically and physiologicallyneeded with relatively no support elsewhere, thus, affording complete freedom of foot. action.

A further object is to provide proper support and balance in a shoe madeso as to raise the heel of the foot higher than the ball of said foot wherein an entirely new shoe element takes'the place of the conventional shoe heels and shanks, and wedges in the art.

Another object of the invention is to provide elevated support for a shoe by means of a chair giving substantially rigid support only to the heel and base of the fifth metatarsal of the wearer. It is essential in this construction that there be no support, or at least not a rigid support, under the first to the fourth metatarsal] bases, and no support forward of the fifth metatarsal base except a flexible sole construction without any stiffening shank.

More particularly, an object of my invention may be described as intending to provide a shoe construction comprising a substantially firm self supporting heel and post preferably bridged or otherwise unified to form a chair adapted to sustain the weight of the wearer imposed at the heel and base of the fifth metatarsal respectively but offering no more than a yielding, readily deformable support at the bases of the other metatarsals in the arch, and between the base and head of the fifth metatarsal, and a flexible sole construction extending forward of the post upon which sole the heads of the five metatarsals can rest, the sole construction having a flexible joint with the post and unencumbered-with any stiff shank reinforcement, whereby interference with the flow and functionofrthe muscles of the foot is avoided, and an upper attached to. the heel and post.

Still further and additional objects and features of the invention will be apparent from the following detailed description read in conjunction with the accompanying drawings.

.In the drawings:

Figure 1 is a sectional view of a shoe embodyprimary bone 'so-called Chinese heel.

Figure 8 is a view similar to Figures 6 and 7 of a still further modification in which the chair subsequently described in detail is made in three pieces.

Referring to the drawings, I have illustrated in Figure 1 a shoe embodying my invention which includes an upper in, which may be constructed of leather, fabric, rubber or any material suitable for the manufacture of shoes, slippers, boots, pacs, and the like. An insole ii may be attached to .the upper by cementing, stitching or other practices employed in the art. A chair I2 com prising a heel i3, a post id, and a bridge 15, may be cemented, tacked or stapled to the upper. This chair can be constructed of any material firm enough to support functioning body weight and possessing characteristics that permit proper shaping to fit the shoe. For example, wood, leather, cork, fiber compositions, rubber compositions, plastics, and the like will be found suitable. Obviously, the chair may be left natural, or it may be enameled, or otherwise decorated, or may be covered with leather or fabric. This is inconsequential to the invention. The chair at the point of ground contact may be soled as at l6 and ill with rubber, leather or equivalent sub- The chair'can be adapted to any height feasible in lifting the heel off the ground.

stances.

An outsole is made of leather, rubber, plastics, or other suitable material may be attached to the chair at W by cementing or nailing, or both. A shank is not needed, and inaccordance with the invention, should be omitted.

The plan outline of the chair is illustrated in Figure 2. This chair is relatively wide at the heel is and narrow at the post H, the latter being located adjacent the outside of the shoe.

These two elevated supports, as located, are essential. The heel bonepf the foot centers at about the circle 2@, and the base of the fifth metatarsal at about the circle 2|. As seen in side elevation, Figure l, the heel should be somewhat higher than the post. The bridge [5 provides a ciently long base, thus resembling in profile a Dutch heel.

Between the post it and the ground support protected by the sole l8) for the heads of the five metatarsals, the sole construction is flexible. Inside of the post there is no support for the foot save the upper Iii which is soft, flexible, and deformable, accommodating the inner arch muscles and ligaments of the foot without restraint, avoid- 4 ing pressure on nerves, and permitting free circulation of the blood and lymph.

The measurement from the heel bone 20 to the base of the fifth metatarsal 2i and from the latter to the heads of the five metatarsals varies in different feet, and consequently arbitrary measurements. would add nothing to the disclosure of my invention. The necessary measurements will be incorporated in the last, according to foot size and characteristics, having reference to the principles necessary to an embodiment of my invention. The essence of my invention resides in a shoe, regardless of its detailed Pattern and construction, providing elevated support for the heel bone and base of the fifth-metatarsal,

sole protection for the heads of the five metatarsals, and either no support or a flexible, readily yieldable and deformable support for the remainder of the arch. r I 0n the inner side of the shoe the heel isonly.

long enough to provide adequate support and balance for the heel bone, described anatomically as the 'calcaneum. If extending too far forward on the inside of the shoe the heel would encroach on, and interfere with, proper function of ligaments and muscles that are attached to the heel bone as well as the long foot muscles that fit into the foot from above at this area. Either an abrupt reduction of the heel width, or a gradual curved reduction as shown in Figure 2, may be employed.

On the outside area the heel is just long enough tosupport the heel bone in the rear, and

ing the full functional advantage Of the invention. a

The chair and outsole of a shoe made in accordance with the invention may be conveniently embodied in one unit as is illustrated in Figure 3. The chair may be made of one kind of-plastic, and the sole of another, or both of the same kind, or both may be molded of rubber or otherwise formed integral.

The invention may be used in a platform or cushioning midsole construction, as, for example, illustrated in Figure 4. In this modification it may be found convenient to slotthe chair at 3B and-insert the lower edges of the upper as at if in Figure 5. In this case, an'outsole 32 can be attached to the lower surface of the midsole or platform section 33 and extend it in slightly to rest upon the post Ma within a slot 34.

If the chair and midsole are made integral, certain materials may be used which in a thick body such as the chair will be'relatively firm and non-yielding, but in a thinner sheet such as the midsole 33 will be relatively soft and readily flexible. If desired,'the chair and midsole can be made of different materials, and the midsole or platform can overlie the chair ina manner similar to certain well known constructions employing wedge heel raises.

The shoe construction shown and described are by way of example only, to illustrate the invention. The chair can be applied to shoes manufactured by any process of sole attachment or made of shoe materials of any description. It

provides a firm foundation for the foot yet per-' Considering the heel, post and.

body weight and does not interfere with functional properties of the foot there is freedom of action when the foot is in motion. walking or running the chair is lifted oif the ground as in ordinary heel or wedge. Its advantage from the standpoint. of health is that there is no shank, or wedge on the bottom of the shoe to create tension and stiffness with their damaging effect on the foot. Reduced to a descriptive formula the chair provides rigidity and support under the foot when and where it needs it and permits freedom of foot action when and where it needs it in the heel to ball area.

The fifth metatarsal bone is rigidbetween the base and head in all feet. This is true of all five metatarsal shafts. This anatomical fact is the reason no shanks are necessary between the ball of the foot and the forward portion of the chair. Any shank or unnecessary stiffening in this area will interfere with free foot function. Incidentally, the five metatarsal shafts are very strong and natural shanks within the foot itself. Inasmuch as the chair is primarily for the purpose of supporting weight bearing bone contact points without interfering with function it is vital that minimum pressure be exerted on muscles, ligaments, nerves and blood and lymph circulation. The design of the chair provides for the first time a shoe in which foot support does not interfere with foot function and vice versa.

The chair permits'of maximum development of comfort values inherent in lasts, patterns and materials because of its maintenance of correct structure and function at all times.

In addition to its scientific value, the chair effects economy in manufacture. Outsole units, if employed, need run only from the forepart of the shoe to the juncture with the forward end of the chair. The elimination of a shank is a saving. The chair takes less material than a wedge in the outsole and eliminates that portion of the wedge running from the ball of the foot to the fifth metatarsal base, as well as the conventional sole and heel area'conventional width.

The chair can be made to fit the shoe with greater ease than either a wedge heel or shank that runs from heel to ball, This is true because any unit that runs from heel to ball must fit the long curve in the bottom of the last which bends at the base of the flfth'metatarsal with an angularity depending on the height at which the heel of the foot is elevated off the ground. The chair has but a relatively slight curve at the top line from front to back because it runs only from the heel to the base of the fifth metatarsal and not forward to the ball of the foot as is the case with the sharply curved wedge or shoe shank.

The chair can be adapted in its design to fit last and shoe bottoms in which are found variations for various foot types and classifications, even those in the; deformed category. Furthermore, all feet, regardless of type or classification, not in the severely deformed category have similar functional machinery and characteristics such as the same ligaments, muscles, nerves and blood and lymph systems. The chair, when used on shoes correctly designed and manufactured in all parts, beginning with the lasts and patterns, provide for the first time shoes that are made for feet as they really are and not conceived and When manufactured in ignorance of foot case with most shoes today.

In the modification resembling the Dutch heel shown in Figure 6, the top plan surface-40 of the chair Ha substantially conforms to'the top plan surface of the construction shown in Figures 1,

facts. as is the lnand 2, but the heel and post are unified so I .tion the top that in side profile it has the appearance of a Dutch heel. A

Figure 7 embodies the invention with a unified heel and post l2b in a construction having the side profile of a Chinese heel. In this modificaplan surface 4| is the same as in the other forms of the invention.

Figure 8 shows a still further modification of a chair in which the heel 42 and post 43 are bridged by a separate bridge element 44, the latter being secured to the heel and post by any suitable means, an example of which is by screws 45.

While the illustrations in the drawings show the chair to be made of material having considerable body thickness, the chair may. clearly be made with relatively thin walls and hollow of metal, suitable plastics, or any matbial sufficiently rigid and strong to sustain'the required stress, and such material may be decorated with filigree, or with other cut-away portions, or set with jewels, or otherwise ornamented. In case of more expensively decorated chairs they could be transferred from one shoe to another, providing the remainder of the shoe was designed for the chair.

From the foregoing it will be seen that I have provided a new and novel type of elevated support for shoes wherein substantially rigid sup-' port is given to the heel and base of the fifth metatarsal and substantial freedom of motion is given to the balance of the foot.

In the appended claims the word chair will be understood to encompass a member for elevated support in men's, women's and childrenfs shoes and the like wherein said elevated supporting member gives substantially rigid elevated support only to the heel and base'of the fifth metatarsal.

Although 'I have herein shown and described my invention in what I have conceived ,to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent methods.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1, In combination with a shoe an elevated supporting member mounted to give substantially rigid elevated support only to the heel and base of the fifth metatarsal of the foot and avoiding rigid support of the other metatarsals.

2. A shoe construction comprising a substantially firm self-supportin heel and post located and adapted to sustain the weight of the wearer imposed at the heel and the base of the fifth metatarsal of the human foot but offering no support at the other metatarsals in the arch, a, flexible sole extending forward of said post upon, which sole the heads of the five metatarsals can rest,

gara es 3. An element for a shoe or the like consisting of a chair which comprises a heel providing a support for the heel bone of the foot, a post of size and location to support only the base of the fifth metatarsal of the foot, and a bridge interconnectingsaid heel and post. I

4, An element for a shoe or the like consisting of a chair which comprises a heelproviding a support for the heel bone of the foot, a post of lesser height than the heel and of size and location to support only the bas of the fifth metatarsal of the foot, and a bridge interconnecting said heel and post. r

5. An element for a shoe or the like consisting of a chair which comprises a heel providing a support for the heel bone of the foot. a post of j lesser height than the heel and of sizeand location to support only the base of the fifth metatarsal of the foot, and a bridge rigidly interconnecting said heel and post.

6. An element for a shoe or thelike consisting of a chair which comprises a, relatively wide heel providing a support for the heel bone of th foot, a relatively narrow post of size and location to support only the base of the fifth metatarsal of a tapering section interconnecting same, a readily l5 flexible sole extending forward'from said supportan integral substantially firm elevated supportingmember having an area for the support of the heel bon of the foot, an area of lesser elevation and narrower width. located to support substantially only-the base of the fi-fthmetatarsal of :the foot, and a tapering section intermediate the two said areas and interconnecting same.-

8. Ashoe construction comprising: an integral substantially firm elevated supporting member having an area for'the support of the heel bone of the foot, an area, pf'lesser elevation and narrower width located to support substantially only the base of the fifth metatarsalof the foot, and

. ing member. unencumbered-by any stiffening the foot, and a bridge interconnecting said heel y and post and tapering in width from the heel to the post. I

7. An element for a shoe or the like comprising support only to the heel'and base of the fifth metatarsal of the foot, theoutsole and elevated 1 support unit being attached to the upper.

NROBERT E. CAHILL 

